1. Technical Field of the Invention
The present invention relates to a bolus for oral administration to ruminant animals, such as cattle, sheep, goats and deer, with a biologically beneficial substance, i.e., a substance with beneficial nutritional or therapeutic effects.
2. Description of the Prior Art
In the prior art known to the inventor, Laby, U.S. Pat. No. 3,844,18,5, issued Oct. 29, 1974, relates to a plastic capsule, which splits into two interconnected parts to enable retention in the rumen. Laby specifically teaches against the use of a ballasted matrix. Furthermore, Laby discloses, apart from a splitting aspect, only the use of a plastic or gelatin capsule, of which the present invention specifically seeks to avoid, as further discussed herein.
Whitehead, U.S. Pat. No. 5,342,576, issued Aug. 30, 1994, discloses an aluminum sheath enclosing pellets of beneficial substances. The magnesium manganese alloy of Whitehead, other than enclosing pellets of beneficial substances, would appear to have little in common with that of the present invention.
Lucas, U.S. Pat. No. 4,505,711, discloses a deposit device for delivering biologically active substances to the digestive tract, which consists of a kind of metal or nylon bobbin carrying a cylindrical matrix of a wax, in which beneficial substances may be incorporated. The bobbin is intended to be the ballast, whereby the bolus is retained in the ruminant stomachs. Unlike Lucas, which utilizes a wax matrix, the present invention employs a rosin, such as pine rosin, which differs substantially from a wax. Wax is generally soft at room temperature, while the rosin of the present invention is hard and brittle at room temperature. In any event, in contrast to Lucas, the present invention does not require use of a bobbin to carry the base matrix.
Finally, Fezzi et al., U.S. Pat. No. 5,068,108, issued Nov. 26, 1991, discloses a controlled release protective matrix for zoo-technical and veterinary use. More specifically, Fezzi et al. discloses a carrier matrix obtained by processing a lipidic material. The matrix takes the form of a paste and is quite incapable of use as a bolus for oral administration. The Fezzi et al. matrix, in contrast to the present invention, is intended to be used as an additive to animal feed or fodder. The non-self-supporting Fezzi et al. paste is not capable of providing a prolonged release of a beneficial substance, even if carried by a bobbin, as disclosed by Lucas, U.S. Pat. No. 4,505,711, or a sheath, as disclosed by Whitehead, U.S. Pat. No. 342,5576.